Path Lab-Diseases of Infancy & Childhood Flashcards
Aside from hyaline membrane disease, what other (CNS) abnormality may present in prematurity?
Paraventricular hemorrhage, the cells that line the ventricles are very sensitive to disruption in preterm babies. This results in brain parenchymal necrosis, seizures and brain damage.
A 25-year-old G2 P1 female at 32 weeks gestation presents with a history of cessation of fetal movement. The infant and placenta were delivered vaginally. Ultrasound confirmed fetal demise and indicated a hydropic infant and large placenta. What is your differential in a hydropic infant delivered to this mother?
This is a hydropic infant (generalized edema, or anasarca). Edema is a result of hemodynamic instability that causes transudation of fluid. This can be due to increased hydrostatic pressure or decreased oncotic pressure. A common cause of hydrops in a mother having a second child is Rh incompatibility, which causes hydrops via damage to the liver (loss of oncotic pressure) and damage to the heart. Another cause is ascending TORCH infection that causes chorioamnionitis not affecting the villi. A final cause is TORCH infection spread via the chorionic villi in the placenta that causes villitis.
This 850 gm female twin “A” infant (see case 3 for twin “B”) developed respiratory distress shortly after birth. She was given an intra-tracheal preparation of surfactant and was placed on high-frequency jet ventilation and 40% oxygen and was slowly improving until the third day of life when she was noted to have increasingly poor muscle tone and a diminished Moro reflex. On the fifth day the infant developed convulsions leading to a cardiac arrest. What is the pathophysiology that caused this child’s respiratory distress?
Acute severe injury to capillary endothelium and type I/type II pneumocytes causes hemorrhage, leakage of fluid and protein across the alveolar membrane and formation of hyaline membranes due to aggregation of protein and necrotic cell debris.
Twin “B” was an 825 gm female who also developed respiratory distress, was given surfactant and placed on a ventilator where she improved rapidly and was extubated at 4 days of age. Oral feedings were begun the same day. On the sixth day of life her abdomen became increasingly distended and she passed a number of soft bloody stools. She became hypotensive and lethargic and was noted by abdominal x-ray to have free air in the abdomen. Her feedings were stopped and a nasogastric tube was inserted to decompress the bowel. A portion of her bowel was resected and oral feedings were resumed 10 days later with complete recovery. What causes the condition seen in this child?
This child has neonatal necrotizing enterocolitis. Absence of microbiome in the child’s bowel puts the gastric mucosa at risk for serious bacterial infection. Necrosis of the bowel allows air to track beneath the mucosa, cause perforation and cause pneumoperitoneum. Open pathway from the bowel allows for pneumoperitonitis and sepsis.
A three-year-old boy was noted to have a firm painless mass on the left side of the abdomen. Blood pressure was 140/90. CT of the abdomen showed a large intrarenal mass on the left side that appeared to be demarcated from the normal kidney. Histology is shown below. What is your diagnosis?
Note the 3 histologic parts: blastema (small round blue cells), stroma (cartilaginous), and epithelial elements (abnormal glomeruli and tubules). This is characteristic of Wilms tumor.
A one-year-old white female infant was admitted due to respiratory difficulty. Her weight gain and growth had been in the lower range of normal. The parents complained of occasional malodorous stools. Antibiotic therapy was begun, but the infant developed a Pseudomonas infection, which could not be controlled, and she died with a panlobar pneumonia. 38 week gestation, 7lbs, APGARS 8/9 at birth; hospitalized overnight at 3 months for RSV. Mother and father healthy; mother’s brother died age 4 of “breathing problems”; sister has asthma age 4. Thin pale infant with non tender slightly distended abdomen; nasal flaring and intercostal retractions present. WBC 16,800. Chest radiographs show diffuse pulmonary consolidation ; autopsy shows marked mucous plugging, lung combined weight 175 gm (normal for age 110 gm). What is causing this child’s condition?
Mutation in the CFTR gene causes abnormal chloride channels. If you can’t pump NaCl into the ducts, you can’t hydrate secretions. Secretions get thick and they clog up the duct. This happens in hepatic bile ducts and pancreatic ducts too. In the sweat glands, the opposite happens and Cl- is supposed to be brought out of secretions and back into the cells. If this doesn’t work then kids get salty skin.
Causes of non-immune fetal hydrops?
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These are normal 3rd trimester chorionic villi. What would this look like if the mother had an infection that could cross the placenta?
Villitis results from hematogenous spread. Chorioamnionitis results from ascending infection.. You would see scattered inflammatory cells within the villi, necrosis, fibrosis and calcifications. Note that a viral infection would yield a lymphocytic monocyte infiltrate.
What type of villitis is this?
CMV. Note the intranuclear inclusions with a surrounding halo and intracytoplasmic inclusions. Note the cellular enlargement.
Where else might you see CMV inclusions in a fetus?
Bile duct, renal tubules and periventricular calcification.
What would you see on histology of the amnion in chlamydia or gonorrhea?
Most ascending infections are bacterial and you would see an acute neutrophil response and chorioamnionitis.
Common areas affected in the fetus by TORCH infections?
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What L:S ratio are you looking for in a prospective preterm baby?
2:1 unless the mother is diabetic. In a diabetic mother you would want to see a ratio of 3:1.
What about this image makes you think it is no a pneumonia?
This is hyaline membrane disease. There is not a lot of inflammation in hyaline membrane disease, just necrosis, capillary damage, hemorrhage and exudate.
What contributes to the abnormal alveolar development in this child who had hyaline membrane disease at birth? What non-pulmonary symptom can result from too much oxygen?
This is bronchopulmonary dysplasia. High levels of oxygen are detrimental to the further development of alveoli which is seen on the right. Ventilation can cause trauma to the alveoli also. On the left side of the image you see fibrosis from treatment of RDS. Retinopathy and blindness can also result from oxygen toxicity.
What would you expect to see on histological examination of this newborn’s bowel?
Air dissecting under intestinal mucosa, cysts in the serosa and transmural inflammation and necrosis.
Treatment for this patient with Wilms tumor?
Removal. Anaplasia is a sign for poor prognosis and poor response to chemotherapy. Vascular invasion of the renal pelvis also indicates a poor prognosis.
What histologic findings would you expect to find in this patient who had cystic fibrosis?
Ductular and lumenal obstruction by mucus plug provides a fertile ground for bacterial growth and you may see acute inflammatory infiltrate, abscesses
Why do patients with cystic fibrosis present with malabsorption and steatorrhea?
Initially the ducts become dilated and cystic. As time goes on the pancreatic parenchyma is replaced by fibrosis and exocrine glands are destroyed.
